Micrometer frame



March 21, 1961 sOUcY 2,975,523

MICROMETER FRAME Filed Aug. 28, 1958 2 Sheets-Sheet 1 INVENTOR. Ge orge H. Solzqy ATTORNEYS.

MarchZl, 1961 G soucy 2,975,523

MICROMETER FRAME Filed Aug. 28, 1958 2 Sheets-Sheet 2 will Hum 2/0 m lfl WWW l IN V EN TOR.

Qeorge f7 Saucy y/amzm ATTORNEYS.

Estates This invention relates to a micrometer and particularly to the frame of the micrometer.

Heretofore, the frame of a micrometer has been of uniform thickness throughout its U shape extent with a small bulge at the end of one of the arms of the U for receiving the anvil which is mounted therein. The end of the other arm of the U is enlarged and of cylindrical shape, and has a bore for the reception of the barrel and spindle which extend into this enlarged portion of the end of the arm. In finishing a micrometer frame of this shape, it is necessary to file or cut and separately finish the enlarged curved ends of the arms and separately finish the opposite faces of the frame.

One of the objects of this invention is to reduce the operations necessary in the finishing of the frame, also to eliminate a filing or cutting operation on the frame which has heretofore been necessary in and about the enlarged end of the frame which receives the barrel.

Another object of the invention is to provide a frame which will have a good balance in the hand.

Another object of the invention is to provide a frame in which the clamp may be more concealed than the shape of frame heretofore used.

With these and other objects in view, the invention consists of certain novel features of construction as will be more fully described and particularly pointed out in the appended claim.

Figure 1 is an elevation of a micrometer incorporating this invention.

Figure 2 is a top-plan view thereof.

Figure 3 is an elevation with the thimble removed and illustrating the barrel as attached to the frame.

Figure 4 is a bottom-plan view of Figure 3.

Figure 5 is a top-plan view of Figure 3.

Figures 6, 7, 8, and 9 are sections taken on lines 6-6, 77, 88, and 9-9 of Figure 3.

Figure 10 is an elevational view, largely diagrammatic, illustrating the manipulation of the frame of the micrometer in grinding the same.

Figure 11 is a section on line 1111 of Figure 10.

In proceeding with this invention, I provide a frame which is generally symmetrical about a plane passing centrally through both of the arms and bridge portion which connects them of the U frame. The opposite faces of the frame are tapered so as to diverge from the outer bight of the frame toward the ends of the arms and at the same time taper from the barrel arm to the anvil arm. By this arrangement, I may lay one side face of the frame upon a grinding surface and grind that face of the frame and then slowly rotate the frame with the ends of the arms, in contact with the grinding surface, eventually laying the opposite side of the frame on the grinding surface to perform the grinding operation, thus using for such finishing a single grinding operation, to obtain the desired surface on the opposite faces and ends of the arms and leaving only the inside and outside edges of the frame for further finishing.

With the reference to the drawings, 10 designates generally the frame which is of U shape having an anvil arm 11 and a barrel receiving arm 12. An opening 13 as indicated in dotted lines (Figure 3) is provided for mounting an anvil 14 in position in this arm 11, while in the cut arm 12 there is an opening 18 for the reception of the reduced end of the barrel 15. A spindle 16 carried by the thimble 17 will extend through the barrel and be adjustable within the frame.

As may be seen in Figures 7, 8, and 9, the frame is tapered with its opposite faces 20 and 21 converging from the ends of the frame adjacent the spindle axis toward the bight portion 22 of the frame. In other words, the thickest portion of the frame is adjacent the spindle axis while the thinner portion of the frame is along the bight or bridge portion 22 which connects the arms. Also, there is a taper on the opposite faces of the frame, as seen in Figure 6, from the barrel carrying arm toward the anvil carrying arm; thus as seen in Figure 7, the outer face 25 of the bridge 22 will be narrower than the inner edge 23 (Figure 7) of the bridge. The amount of the taper which has been found satisfactory is usually a five degree taper in both directions. By this arrangement the frame is symmetrical about a plane passing through the center of both of the arms and the bridge as may be seen from the showings in the sections, Figures 6 to 9 inclusive.

A slot 26 is shown in barrel arm 12 through which the finger piece with knob 27 extends for clamping the spindle 16 in position. This is more fully described in a copending application which I filed of even date with this application.

In Figures 10 and 11 I have illustrated a grinding surface 30 which may be a rotary grinder on shaft 31 or some suitable moving grinding surface, and I have shown the frame designated generally 10 having its face 20 in engagement with this surface that movement of the grinding surface with reference to the frame will grind this surface. The end of the barrel arm 12 is designated 24 and the end of anvil arm 11 is designated 24' and each is on an arc to be tangent with the opposite faces 20 and 21. After a sufiicient grinding action has been. had on the surface 20, the frame 10 may be rotated about the axis 32 (Figure 10) causing the surface 24 at the end of the barrel arm and surface 24 at the end of the anvil arm to be ground, the timing being such that a sufiicient grinding will be performed upon these arcuate surfaces 24 and 24' as such rotation occurs, finally causing the surface 21 to engage the grinding face 30 and be ground. This may be an automatic operation by reason of the shaping of the ends of the arms of the frame and the taper provided. Thus the shape of the frame lends to this automatic operation by which all of the surfaces except the inside and outside edges 23 and 25 may be finished. I have found by this method of proceeding that a saving of time in finishing may be had.

I claim:

In a micrometer, a frame of U shape with a barrel arm and an anvil arm connected by a bridge portion and generally symmetrical about a plane passing centrally through both arms and bridge portion, the opposite outer faces of the frame diverging on a taper from the outer bight of the frame toward the ends of the arms and at the same time tapering from the barrel arm to the anvil arm and the ends of the arms having arcuate surfaces substantially tangent to the opposite faces of the frame, and tapering to provide partly frusto conical portions with the taper of one portion being a prolongation of the taper of the other portion.

References :Cited in the file of this patent UNITED STATES PATENTS 1,288,788 Zimmermann Dec. 24, 1918 1,486,342 Hoke Mar. 11, 1924 1,713,743 Challet May 21, 1929 2,666,263 Laserson Jan. 19, 1954 

